Electronics

Electronics

Maxwell – Electric Motor – Machine Toolkit – Efficiency Map – Voltage/Current Settings

    • meghanty
      Subscriber

      Hello again,

      I have a second question for today following the first post about the electric motor efficiency map toolkit found here: https://forum.ansys.com/forums/topic/maxwell-electric-motor-machine-toolkit-efficiency-map/

      I am modeling BLDC PM delta-wound electric motors, which in reality will be running square current PWM waves from a motor controller. When running the toolkit, the voltage/current options given are as follows: Sinusoidal PWM, third harmonic PWM, Space Vector PWM, and Line-Line RMS. I understand the first two options, but have been unable to find solid information online confirming how the last two options are treated and whether they are right for my designs. Could I also possibly set up the square-wave voltages through an external circuit design attached to the windings?

      Following from this, do any of my winding/excitation inputs get used or are they simply overridden by the toolkit? After the toolkit was done operating, the winding settings changed from 'voltage' to 'current' with this line given for the current function:
         Imax_TSC * sin(21*Position+Gamma_TSC-0.0deg+80.0deg)

      As before, thank you so much to all who spare their time to help,
      Meghan

    • xzhao
      Ansys Employee

      Hi Meghan,


      The Machine Toolkit currently only supports 3-phase Synchronous PM machines/Induction Machines. All the options under "voltage control" are modulation strategies. Both the Space vector PWM and Line-Line RMS modulate the DC voltage to sinusoidal voltages. Only that different modulation methods would have different voltage utilization ratios and etc. So square-wave voltages are not applicable in the Machine Toolkit.


      The toolkit would overwrite any excitation settings in your original design. It will create an external circuit based on the selected modulation method and use the toolkit defined sweep parameters, for example, "Imax_TSC", "Gamma TSC" and "Speed_TSC" to set up the excitation and motion in the new design for efficiency map calculations. 

    • meghanty
      Subscriber

      Thank you very much for your reply xzhao!

      If I were to run a BLDC design in the synchronous mode, do you think it would still give a good approximation of performance for the BLDC's performance? As I understand the only differences would be the input voltage being sinusoidal (third harmonic would be best) instead of square, and the back-EMF not being trapezoidal as would be expected in a BLDC motor.

      For more exact efficiency maps I'd have to manually produce multiple torque-rpm graphs at different voltages and interpolate the efficiency values between the different plots to create the topographical map, yes? Do you know of any manuals/tutorials that could help me in producing these torque-rpm graphs for BLDC motors?

      I greatly appreciate your the time you're putting into helping. Thank you very much!
      Meghan

Viewing 2 reply threads
  • You must be logged in to reply to this topic.